/****************************************************************************
 *
 *   Copyright (c) 2019 PX4 Development Team. All rights reserved.
 *   Copyright (c) 2025 H743 Flight Controller Project. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name PX4 nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

#include <px4_platform_common/px4_work_queue/work_item.hpp>
#include <px4_platform_common/px4_work_queue/work_queue.hpp>
#include <px4_platform_common/px4_work_queue/work_queue_manager.hpp>
#include <px4_platform_common/hrt_call.h>

#include <math.h>
#include <float.h>

// Forward declaration for debug_printf
extern "C" int debug_printf(const char *format, ...);

namespace px4
{

WorkItem::WorkItem(const char *name, const wq_config_t &config) :
	_item_name(name)
{
	// Initialize intrusive list nodes
	sorted_list_node.sibling = nullptr;
	queue_node.next = nullptr;

	if (!Init(config)) {
		debug_printf("[WorkItem] %s: init failed\n", name);
	}
}

WorkItem::WorkItem(const char *name, const WorkItem &work_item) :
	_item_name(name)
{
	// Initialize intrusive list nodes
	sorted_list_node.sibling = nullptr;
	queue_node.next = nullptr;

	px4::WorkQueue *wq = work_item._wq;

	if ((wq != nullptr) && wq->Attach(this)) {
		_wq = wq;
	}
}

WorkItem::~WorkItem()
{
	Deinit();
}

bool WorkItem::Init(const wq_config_t &config)
{
	// Clear any existing first
	Deinit();

	px4::WorkQueue *wq = WorkQueueFindOrCreate(config);

	if ((wq != nullptr) && wq->Attach(this)) {
		_wq = wq;
		_time_first_run = 0;
		_run_count = 0;
		return true;
	}

	debug_printf("[WorkItem] %s: work queue '%s' not available\n", _item_name, config.name);
	return false;
}

void WorkItem::Deinit()
{
	// Remove any currently queued work
	if (_wq != nullptr) {
		// Prevent additional insertions
		px4::WorkQueue *wq_temp = _wq;
		_wq = nullptr;

		// Remove any queued work
		wq_temp->Remove(this);

		// Detach from work queue
		wq_temp->Detach(this);
	}
}

void WorkItem::ScheduleClear()
{
	// Set cancel flag (in case item is already popped from queue but not yet executed)
	_should_run = false;

	// Remove from queue if still there
	if (_wq != nullptr) {
		_wq->Remove(this);
	}
}

float WorkItem::elapsed_time() const
{
	if (_time_first_run == 0) {
		return 0.0f;
	}

	hrt_abstime now = hrt_absolute_time();
	hrt_abstime elapsed = now - _time_first_run;
	return elapsed / 1e6f; // Convert to seconds
}

float WorkItem::average_rate() const
{
	const float elapsed = elapsed_time();

	if (elapsed > FLT_EPSILON && _run_count > 1) {
		const float rate = _run_count / elapsed;

		// Check if rate is finite
		if (rate > FLT_EPSILON && rate < FLT_MAX) {
			return rate;
		}
	}

	return 0.0f;
}

float WorkItem::average_interval() const
{
	const float rate = average_rate();

	if (rate > FLT_EPSILON) {
		const float interval = 1e6f / rate; // Convert to microseconds

		// Check if interval is finite
		if (interval > FLT_EPSILON && interval < FLT_MAX) {
			return roundf(interval);
		}
	}

	return 0.0f;
}

void WorkItem::print_run_status()
{
	debug_printf("%-29s %8.1f Hz %12.0f us\n",
		_item_name,
		(double)average_rate(),
		(double)average_interval());

	// Reset statistics
	_run_count = 0;
	_time_first_run = 0;
}

} // namespace px4

